how does this circuit produce four sounds ?
hi everyone
my friend is interested in doing this circuit but he need to understand how it's working
this is the circuit diagram
http://www.circuiteasy.com/animation/four%20tone%20siren%20circuit.gif
is it need 3 switches ?
and what the benefit of the transistor here ?
waiting for your help ^^
Discussions
These links might help you.
http://electroschematics.com/4820/um3561-siren-generator-design-2/
http://electroschematics.com/wp-content/uploads/2010/03/UM-3561-Datasheet.pdf
The key is the chip, where all the magic happens. The sounds are selected by the position of the switches. The transistor is a very basic amplifier.
It uses 4 different states to get the four sounds. You can do this with 2 Spdt switches. I'd use switches with the center off. The transistor is most probably an amp.